The beginning looked good, the attendance was
prettydecent,
about μ+5σ, and I was pleased and flattered to see
the faces of
somepeople
who normally don't attend these talks. But soon came the first "incident",
five minutes through the talk. I saw my esteemed colleague, K., flagrantly reading
a textbook. Now, you may think that I am a weirdo, but I get annoyed and offended by people who
do their own work during other people's talk, and especially during mine. So I nicely asked
K. to close the book, and pay attention. In response, he said:

It took me a few moments to recover from this defection,
and then came the second "incident". Sitting at the back was, L., one of my favorite members
of the department, who in addition to being a great mathematician (and perhaps the best teacher in our department)
is (usually) a very good man, once again flagrantly, grading exams. I asked him to stop
grading, and pay attention, and he got angry too, took along his exams, and left in a huff.
Shortly after there was another defection (an obvious corollary), and yet-another-one,
less obvious, who left saying that she "has heard this lecture before".

By then, I was completely distracted, and barely made it to the
end
of the micro-century
(52 minutes and 35 seconds) that I pledged my talk would take.

I hereby publicly apologize to K. and L. It is all due to a misunderstanding. I naively believed that
people attend talks to learn something new, and are willing to pay full attention. But this is
only the ostensible reason. Quite a few people go to math talks for the same reason that I sometimes
take the train to Washington, D.C., ostensibly to do research in the Library of Congress, but the real reason is that
it guarantees me six hours of solid work time,
away from computers (I don't own a laptop) and the distractions of the
internet. For the same reason, I often go to Starbucks or Panera (without a laptop!), not to
have coffee, but to work in peace.

So K. needed to prepare his next class (the next meeting of which, by the way, is Tuesday), and finds it
much more efficient to do it during a seminar or colloquium talk. Similarly, L., being the great
(and conscientious!) teacher that he is, needed to grade as many exams as possible, so that he would
be able to return them promptly (and leave some time during the weekend for his numerous hobbies).

In further defense of both K. and L., may I add that they probably wouldn't mind
if people behaved like they did during their talks, and may not even notice it.

But for those people, like myself, who do mind, there is a very simple solution,
that I have already used many times-but forgot to do it this time-to prevent being
offended, and in retribution, offending others. I announce, at the very beginning
of the talk,
the rules of conduct that
I expect from my audience:

You may leave any time. I much rather that you leave than do your own work.

Then I turn my back to the audience, and give them 30 seconds to leave.
If after that explicit warning, I still find offenders, no one takes offense when I command
them to close their laptop or stop grading or whatever.

This policy worked very well during a recent
talk
of mine, where I announced "absolutely no laptops" (for some reason, they cut this part from the video).
It is possible that one or two people left (I didn't see, since my back was turned), but the
remaining people obediently closed their laptops and paid full attention. Then, after about ten minutes, one
guy opened his laptop, and started typing. I immediately went to him and asked
"weren't you here at the very beginning when I announced no laptops?". He said that he was,
so he apparently forgot, or didn't believe that I was serious. Either way, he
smiled, and good-naturedly closed his laptop, and behaved perfectly until the very end of my talk.

I don't think that I will agree to give a Colloq. talk here at Rutgers for some time,
and I doubt, after Friday, that I will be soon asked.
But if and when this will happen, I really hope that I would remember to post the above explicit rules of conduct, and if, God forbid,
I'll forget, please remind me.